This invention relates to disposable diapers. More particularly, this invention relates to disposable diapers adapted to be secured in place by adhesive tabs.
Disposable diapers provide substantial advantages in convenience over diapers intended to be laundered and reused, particularly when they are used away from home. In recent years, many different disposable diapers have been proposed and some have been successful in the marketplace. Typical disposable diaper structures comprise a facing material to be brought into contact with the infant's skin, an absorptive layer of high liquid-holding capacity, and a moisture-impervious backing layer, generally made of a plastic film such as a polyethylene film. Typical disposable structures are shown in U.S. Pat. No. 3,612,055 to Mesek et al. and in U.S. Pat. No. Re. 26,151 to Duncan et al.
As may be seen from the above-cited patents, it has been desired to obviate the problems that are inherent in closure systems utilizing extraneous fasteners such as safety pins, snaps and zippers. To this end, adhesive closure systems have presented acceptable solutions.
One of the most convenient adhesive systems that has been developed to date is the system, shown in the above-cited patents, in which adhesive tabs have fixed ends permanently adhered to the backing sheet at opposite sides of the diaper at one end thereof. Free exposed ends of these adhesive tabs are utilized to effect diaper securement and are protected by cover strips that are readily separable from the exposed adhesive surfaces of the tabs. Disposable diapers using an adhesive closure system of this general type have the disadvantage in that the consumer has to dispose of the cover strips when they are separated from the adhesive strips. This is an inconvenience to the consumer who is placing the diaper on an infant.
An illustrative prior art adhesive system having cover strips permanently attached to the diaper is disclosed in U.S. Pat. No. 3,646,937 to Gellert. The Gellert arrangement has the disadvantage of having the release film on the inside of the diaper, where it can possibly come in contact with an infant's tender skin. Additional disadvantages are the complexities and expense which are added to the manufacturing process by requiring each adhesive closure to be manipulated on the front side, around the edge, and on to the back side of the diaper, instead of handling it on one side only. The closure system illustrated in the Gellert patent also makes it somewhat difficult to secure the diaper around an infant, in that it requires the use of both hands to remove the releasable end of the adhesive tape.
The prior art tab systems have further disadvantages. The permanent attachment of one end of the tab to the diaper limits the ability of the user to place the tab on the diaper to obtain the best fit on each individual baby. By "pre-locating" the placement of one end of the tab on the diaper, the degree of freedom in tape tab placement is significantly limited.
A further problem resulting from permanently attaching one end of the tab on the diaper before using the diaper is tape tab pull-out. This results when a user is fitting the diaper on an infant and pulls on the tape tab with too much force, thereby applying excessive tension to the diaper, which causes diaper rupture and the separation of the tab from the diaper.